Traditional biometrics, such as fingerprints, have been used for (automatic) authentication and identification purposes for several decades. Handwritten signatures have long been accepted as a legally binding proof of identity, and automated signature authentication/verification methods have been available for some number of years. FIG. 1 shows examples of conventional biometrics, specifically a signature 110, a voice (print) 120, a fingerprint impression 130, and an iris pattern 140.
Such biometrics can be used for the automatic authentication or identification of a (human) subject. Typically, the subject is enrolled by offering a sample biometric when opening, for example, a bank account or when subscribing to an Internet service. From the sample biometric(s), a template is derived that is stored and used for matching purposes at the time the user wishes to access the account or service.
A biometric, ideally, will uniquely determines a person's identity. In practice, given a biometric signal, the signal is either associated uniquely with one person, or it reduces significantly a list of possible matching persons. Fingerprints are an excellent biometric due to their uniqueness between individuals. On the other hand, shoe size and weight are poor biometrics, since these parameters obviously have little discriminatory value.
Biometrics may be divided into behavioral biometrics and physiological biometrics. Behavioral biometrics depend on a person's physical and mental state, and are subject to change, possibly rapid change, over time. Behavioral biometrics include the signatures 110 and voice prints 120. Physiological biometrics, on the other hand, are subject to much less variability. For a fingerprint, the basic flow structure of ridges and valleys is essentially unchanged over a person's life time. As an example of another biometrics, the circular texture of a subject's iris 140 is believed to be even less variable over the subject's life than are fingerprints. Hence, there exist behavioral biometrics which to a certain extent are under the control of the subject, and there exist physiological biometrics whose appearance cannot be influenced (the iris 140) or can be influenced very little (the fingerprint 130).
Referring now to FIG. 2A, a typical prior-art automatic fingerprint authentication system 200 has a fingerprint image acquisition device 210 (signal acquisition device 210) that inputs data descriptive of a fingerprint to a biometrics matching system having a signal processing unit 215 for feature extraction, a template extraction unit 220 and a template matching unit 225. Along with the biometrics signal 210, an identifier 212 of the subject is input to the system. During operation of the template matching unit 225 a template associated with the particular identifier 212 is retrieved from a database of templates 230 indexed by identities (identifiers). If there is a Match/No Match between the template extracted by unit 220 and the retrieved template from database 230, a ‘Yes/No’ 240 answer is the output. Matching is typically based on a similarity measure, where if the measure is significantly large, the answer is ‘Yes’, otherwise the answer is ‘No’.
Note that authentication system 200 is not limited to fingerprint authentication, as the system architecture is valid for any biometric. The biometric signal acquisition device 210 that delivers an input signal to the system 200 can be either local to the application on the client, or remote with the matching application running on some server. Hence, the architecture of the system 200 applies to all biometrics, as well as to all networked or non-networked applications.
FIG. 2B shows a prior art identification system 250. A typical automatic biometrics signal identification system 250 takes only a biometric signal from device 210 as input, and contains the signal processing unit 215 for feature extraction, the template extraction unit 220 that extracts a template from the extracted features, and the template matching unit 225. In the case of the identification system 250, only the biometric signal output from the acquisition device 210 is input to the system (not the identifier 212). During operation of the template matching unit 225 the extracted template is matched to all template, identifier pairs stored in database 230. If there exists a match between the extracted template 220 and a template associated with an identity in database 230, this identity is the output 255 of the identification system 250. If no match can be found in database 230, the output identity 255 can be set to NIL. Again, the biometric signal acquisition device 210 can be either local to the application on the client, or it can be remote with the matching application running on some server. The architecture 250 thus applies as well to networked and non-networked applications.
Of course, a single system can be used that executes both the authentication function of system 200 and the identification function of system 250.
Remote individual positive identification using biometrics is becoming widespread. However, several existing business systems and processes require the synchronous participation and authentication of multiple parties in real time. Further, new business processes can be enabled by technology that allows multiple participants to remotely authenticate themselves synchronously.
Generally, the prior art has failed to synchronously authenticate and authorize multiple parties using biometrics, particularly in a network environment.
A general approach to the (abstract) problem of authentication of the identity of a person is to reduce the problem to the problem of authentication of a concrete (tangible) entity related to the person. Typically, the problem of authenticating the identity of a person is reduced to one of a person possessing an some tangible object, e.g., permitting physical access to a building to all persons whose identities are authenticated by possession of a key; or to one of a person possessing some non-tangible information, e.g., permitting login access to a computer system to a person who knows the existence of a user-id and a password associated with the user-id. Some systems, such as ATM banking systems, use a combination of the tangible object (an ATM card) and the non-tangible information (a PIN) to establish the person's identity.
Another approach to positive identification is to reduce the problem of recognizing humans to the problem of recognizing individuals by their distinctive physiological or behavioral characteristics. This approach is referred to a biometric approach. In this case recognizing an individual can mean identifying an individual from a (possibly large) database of identities, or it can mean authenticating an individual's identity by simply verifying that the individual's characteristics are the same or similar to stored characteristics for the claimed identity.
With the growth of the Internet (the Web) over the last few years, many commercial applications are being explored. Such systems are remotely operated and possibly unattended. For example, an e-commerce system may use a fingerprint of the customer to validate a transaction over the web, such as airline ticket purchase. A more familiar example is an ATM banking application where the bank customer is identified through the acquisition of a fingerprint impression or some other biometric information. This, again, is a networked application where customers can withdraw money from an ATM that is owned by a bank other than their own bank. Other examples of remote fingerprint authentication include point of sale transaction authorization based on fingerprints. The business systems and processes that are discussed herein are not limited to authentication of identities through the use of fingerprints.
Beyond authentication problems, where one person has to be authenticated, there are (business) processes where multiple parties have to be authenticated more or less at the same time (synchronously). The problem of authenticating each party's identity can be reduced to that of a person's possession, e.g., keys, or to that of a person's knowledge of certain information, e.g., pins and passwords. Authenticating may also be reduced to combinations of these, where hard copy biometrics (e.g., facial photographs and/or handwritten signatures) in conjunction with real-time observations of the physical characteristics are involved. Recognition by real-time voice observation is another possibility. An example of this multi-tiered approach is an ATM card (possession) coupled with a PIN (knowledge) and also with a signature (biometric). Another example would be a driver's license with a photograph and a signature. Quite often, though, the authentication problem is simply solved through the fact that the parties know one another. In this case the identity may be established through a mutual introduction by a third (trusted) party, and not through conventional means of identification. Conventional identification as considered herein can involve the use of a driver's license, a passport or an ID card such as a corporate identification card, as common examples.
Several exemplary authentication scenarios are now discussed where multiple parties have to be authenticated at the same time (synchronously), or where one or more of the identities have to be authenticated during a period of time (persistent synchronicity). The exemplary authentication scenarios include (a) a vault in a bank that can only be opened by two bank employees, where each employee has a separate key; (b) a locker or safe deposit box in a vault that is opened through the process of a bank employee opening the vault with a key (or two employees with two separate keys) and the safe deposit box owner opening his or her box with a key, in combination with a key used by the bank employee; (c) to eliminate fraud in a store, the cancellation of a transaction is approved by a manager while a checkout clerk confirms the receipt of goods and the customer authorizes the transaction to be credited to the customer's bank account; and (d) a notary public witnessing the execution of a document by verifying the identity of the signer through conventional means, and authenticating the document by signing the notary stamp.
As a further example, many official documents are signed in the presence of one or more witnesses, establishing the fact that the signature is authentic. Examples include deeds, wills and mortgages. Often at least one witness is a notary public.
It is known that in some locations where cellular telephones are pervasive, if a child has lost or forgotten his house key, he can use an intercom-like device at the door which is forwarded to the cell phone of a parent if no one is home. The parent can then remotely open the door through the use of the cell phone. Here the synchronous authentication means are the child's voice (or knowledge such as a PIN) and the parent's voice over the cell phone so that the door is opened when both biometrics are present.
Other such applications in the military and other similar areas exist, where more than one authority is required to execute a transaction, such as the release of a weapon.
In addition to the foregoing multi-party synchronous authentication scenarios, there also exist authentication scenarios where multiple parties have to be authenticated in a sequential fashion, one followed shortly by another. Examples include: (a) the purchase price of expensive items (e.g., automobiles, jewelry) can be negotiated by the buyer and a sales person, approved by signature by a sales manager, and finalized by signature of the buyer and sales person; and (b) large monetary transactions, such as the selling or buying of large blocks of stock in the stock market, may have to be authorized by multiple parties who authenticate themselves through computer passwords. These authorizations need to be done quickly as the share price of securities may be subject to large changes in small amounts of time. Other examples include, but are not limited to, corporate supervisor and manager approvals; government filings such as SEC reports; remote education, student and teacher authentication, continuing education required for job certification; board review of papers, where board members verify their opinion/vote; and a corporate board vote, where a group in authority may cast votes during a virtual meeting.
Note that the foregoing flow processes can be significantly different than the multi-party synchronous authentication scenarios described earlier.
As can be appreciated, traditional one-to-one means of mutual identification based on, by example, the recognition of the physical appearance of a person's face, or the recognition of a person's voice, are largely unreliable. This is true because such identification relies on the fact that one party has introduced himself to the other, or that the parties are introduced to each other by a trusted third party. These introductions are typically not based on true authentication methods, such as verifying a driver's license or a passport. The same problems carry forward, with additional complications, to meetings between multiple parties. An unknown party can easily join a multi-party meeting and not be detected, because each genuine party believes that the unknown party is legitimate if no other genuine party objects to the presence of the unknown party. Further, if any transaction is executed during the meeting (e.g., if the participants vote on an important decision) and the authenticity of the transaction needs to be later proved, it is generally not sufficient to have authenticated the participants at the beginning of the meeting. Instead, it may necessary to prove that all parties simultaneously participated in the transaction. This problem may be referred to as one of synchronous biometric authentication. Further, when the transaction spans a significant portion of time, it is often necessary to prove that parties were not absent during any part of the transaction (e.g., never left the meeting). This problem may be referred to as one of persistent biometric authentication.
A traditional single-party remote authentication is described in U.S. Pat. No. 5,930,804 to Yuan-Pin Yu et al. A system and method is given for Web-based biometric authentication of individuals who are using a Web Client station, where an individual seeks access to a Web Server station. At the Web Client, biometric data from an individual is measured. At an authentication center, a message is received that includes the acquired biometric from the individual seeking access to the Web Server. This biometric data is compared to selected records and if the biometric data sufficiently matches the selected records, the individual is granted access to the Web Server. In this approach multiple parties can be authenticated from different clients by the same authentication server (service), and granted access to one or more transaction servers. However, the transactions of the different parties are treated as separate, unrelated transactions.
As can be appreciated, remote individual authentication using biometrics is becoming widespread. However, several existing prior art business systems and processes require the participation of multiple parties in real time at the same locale. Existing Internet-based systems do not allow for multi-party authentication and authorization in a synchronous fashion. Hence, prior art technology has to be used to schedule a meeting of all the participants. The scheduling of such a meeting can be time-consuming, however, as each meeting participant should have a sufficient period of time available on his calendar during which the meeting can take place. Then, a meeting time and length have to be established which lies within the intersection of all periods of available time for each meeting participant. This becomes a more complicated process the larger the number of meeting participants. Additional problems with these prior art systems and methods are the travel times of the participants, and other unproductive details, which are known to those who are skilled in the art.
One technique for multiple parties to sign a digital document is by the use of certificates. However, these certificates do not support simultaneous real-time signatures, or the presence of the signatories, over an extended period of time. Nor do they link the signatures to the signers in a non-repudiable manner, as fingerprints or other biometrics can do.
As such, new and advanced e-business processes cannot be enabled by existing technology that allows only a single party to authenticate himself or herself.